TextEditor: Setting flags once is enough...

Change-Id: I671d1b0866f2e6ef332a53228bc12b260ba6187d
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/texteditor/basetexteditor.cpp

@@ -7157,7 +7157,6 @@ void BaseTextEditorWidget::setupAsPlainEditor()
     setRevisionsVisible(true);
     setMarksVisible(true);
     setLineSeparatorsAllowed(true);
-    setLineSeparatorsAllowed(true);
 
     textDocument()->setMimeType(QLatin1String(TextEditor::Constants::C_TEXTEDITOR_MIMETYPE_TEXT));